Hoisting tong



.L. NELSON HOISTING TONG May 2, 1944.

Filed April 12, 1943 Patented May 2, 1944 PATENT OFFlCE 2 Claims.

This invention relates to a hoisting tong.

An object of the invention is to provide a tone of the characterdescribed specially adapted for lifting heavy metal plates, beams andthe like.

Another object of the invention is to provide a tong having opposingfixed jaws provided with downwardly converging faces on which aremounted wedge shaped slips whose inner sides are formed with teeth toengage the load between the slips.

A further object is to provide, in a tong, releasable means forautomatically locking the slips in engagement with the load to preventthe unintentional release of the load.

With the above and other objects in view the invention has particularrelation to certain novel features of construction, operation, andarrangement of parts, an example of which is given in this specificationand illustrated in the accompanying drawing wherein:

Figure 1 shows a side view of the tong partly in section.

Figure 2 shows an edge view.

Figure 3 shows a fragmentary cross sectional view taken on the line 3-3of Figure 1.

Figure 4 illustrates the ratchet faces of the locking dogs employed andFigure 5 illustrates one application of the tong to the load.

Referring now more particularly to the drawing wherein like numerals ofreference designate the same parts in each of the'flgures, the numeralsI, I refer to opposing fixed jaws which are formed integrally, at oneend, to the eye 2. These fixed -aws have the faces 3, 3 which convergetoward the free ends of the jaws.

In the inner sides of the jaws I are the longitudinal dove tailedgrooves 4. 4 which extend a the full length of the faces 3. There arethe,

wedge shaped slips 5, 5 which are dove tailed into the grooves. Theinner sides of the slips are parallel and toothed to engage and grip theplate 6, or other load, between them.

Each jaw 5 has the projecting side pins 1, 'l

' elevation of the tong the slips 5 will move downwardly along the faces3 and inwardly into gripping relation with the load; or a pair of tongsmay be engaged with the plate as shown in Figure 5 and connected to theends of the bridle II) which, in turn, may be lifted by the cable 9.

Provision has been made for locking the slips in engagement with theload to prevent premature release of the load. For this purpose theouter side of each slip'is provided with the upwardly pitched ratchetteeth, II. Each fixed jaw I is provided with abore I2 to receive acylindrical dog I3. The inner end face of this dog has transverseratchet teeth pitched oppositely from that of the pitch of thecorresponding teeth ll.

Screwed into the outer end of the bore I2 there is a gland 14 having theinside longitudinal grooves I5. Each dog I3 is attached to an outwardlyextended shank I5 which extends out through said gland and whose outerend is formed into a grip H. The shank has a cross key I8 whose endsextend into the grooves I5.

Located within the bore I2 and surrounding the shank and interposedbetween the gland I4 and the dog I3 there is a strong coil spring I 9.

As the tong is applied to the work the slips 5 will move upwardly alongthe face 3 and outwardly to permit the plate 6, or beam, to readilyenter between the slips. While applying the tong to the work the dogs I3should be pulled outwardly until the cross keys I8 are released from thegrooves I5 and then turned so that the ends of the cross keys willengage the outer ends of th bushings I4. The dogs will thus-be heldretracted with the teeth of the dogs out of engage ment with the teeth II. slips 5 to move freely. When the plate or beam has been insertedbetween the slips the shanks I6 should be turned to align the cross keyswith the grooves I5 and the springs I9 will move the dogs inwardly intoactive position. Upon an upward pull of the cable 9 the slips 5 willmove downwardly along the faces 3 and inwardly into engagement with theload, the teeth II ratcheting past the teeth of the dogs I3 and saidslips will be locked in said position by said, dogs so that the tongwill not accidently or prematurely release the load.

It will be noted from an inspection of Figure 4 that the teeth of onedog I3 are staggered with respect to the teeth of the other dog.. Thishas been done to insure that at least one dog will engage with the teethof the corresponding slip. Otherwise it might happen that the crests ofthe teeth of both dogs might rest on the crests of the This will permitthe- 2 assmaa oorresponding'teeth ll thus allowing a sumcient releasemovement to both slips to permit release oi the load. I! either of theslips is locked against movement the other slip. even though not lockedby its dog. will be held against release movement by the engagement ofits teeth against the load.

The drawing and description are illustrative merely while the broadprinciple of the invention will be defined by the appended claims.

What I claim is:

1. A hoisting tong comprising a pair of spaced .Jaws anchored togetherat one end and having their. other ends free, said jaws having insidefaces whieh'converge toward said free ends, wedge shaped slips mountedon said races and having dovetailed connections therewith and mounted tomove into gripping relation with a load between the slips, one of saidjaws being gland, a cross key on the shank whose end extends into thegroove, a yieldable member in the bore normally-holding the dog inengagement with the corresponding slip, said key being engageable withthe outer end of the gland. when the shank is pulled outwardly andturned, and forming means for locking the dog disengaged from the slip.

2. A hoisting tong comprising a pair 0! spaced jaws anchored together atone end and having their other ends free, said Jaws having inside faceswhich converge toward said free ends,

'dogs mounted on the Jaws and having ratchet teeth, yieldable meansnormally holding the teeth of the dogs in engagement with the teeth ofthe slips, the teeth on one side of the tong pmvidedwithaboreaglandsecuredinthe outer 20 being staggered with respect to the teeth on endof the bore and having an inside longitudinal groove. a dog in said borehaving an outwardly extended shank which extends through the the otherside thereof.

LEE NELSON.

